Inserter systems are typically used to produce a large volume of specific mailings where the contents of each mail item are directed to a particular addressee, such as for banks, insurance companies, utility companies, municipalities and many more. In the type of inserter system relevant to the present invention, a personal insert is inserted in an envelope. A personal insert is a message intended for a particular addressee. The personal insert can be one or more sheets which come from a single source (e.g., continuous roll or fanfold paper or batches of sheets). The sheet or sheets are usually (but not necessarily) folded together and reach the inserter as one group for insertion into an envelope. Other mail items can be added afterwards in the enveloping process.
Inserter systems of this type work most efficiently when run at constant speed. However, the station (e.g., folder or cutter) that supplies the personal inserts cannot work at a constant speed due to the personal inserts having a different number of pages. As a result, the inserter system is forced to operate at varying speeds, which diminishes the efficiency of the system.